Design of Robust Finite-Time Nonlinear Controllers for a n-DOF Robot Manipulator Subjected to Dead-Zone Input Nonlinearities

In this paper, by developing the nonsingular terminal sliding mode control method and defining innovative nonlinear sliding surfaces, input torques are designed for the n-DOF robot manipulator subjected to additive uncertainties and dead-zone input nonlinearities. Suggested inputs are able to steer the configuration variables of joints of the robot manipulator to the desired trajectories within finite times. The global finite-time stability is proven for the closed-loop system of the n-DOF robot manipulator. More, an applicable inequality is derived to determine the total convergence finite time of the closed-loop system and it reveals that the mentioned finite time is dependent on initial conditions and optional parameters of input torques. Finally, designed inputs are simulated on a 2-DOF robot manipulator and obtained results illustrate that suggested inputs fulfill the robust finite-time trajectory tracking objective properly.